Go Back
+ servings
featured m&m peanut butter blondies

M&M Peanut Butter Bars Recipe

Course: Bars, Dessert
Cuisine: American
Prep Time: 10 minutes
Cook Time: 16 minutes
Total Time: 26 minutes
Servings: 16 bars
Calories: 336kcal
M&M Peanut Butter Blondies are a cookie bar that is full of sweet flavor. These blondies are easy to make and perfect as an after dinner treat.
Print Recipe



  • cups all-purpose flour 330 grams
  • teaspoons baking soda 8 grams
  • ¾ teaspoon kosher salt
  • cups brown sugar 266 grams
  • ½ cup granulated sugar 100 grams
  • ½ cup unsalted butter 113 grams, melted (1 stick)
  • cup vegetable oil 67 grams
  • 1 large egg 50 grams
  • 2 egg yolks 28 grams
  • 1 teaspoon pure vanilla extract 4 grams
  • 1 cup peanut butter M&M’s 170 grams, plus more for topping
  • ½ cup creamy peanut butter 135 grams


  • Preheat oven to 350°F. Spray a 9x13-inch baking pan with baking spray. Set aside.
    how to make m&m peanut butter blondies
  • In a medium mixing bowl, whisk together the flour, baking soda, and salt. Set aside
    2¾ cups all-purpose flour, 1¼ teaspoons baking soda, ¾ teaspoon kosher salt
    how to make m&m peanut butter blondies
  • In a large mixing bowl, whisk together the brown sugar, sugar, butter, and vegetable oil. Add in the egg, egg yolks, and vanilla and stir to combine. Add in the flour mixture and stir just until the flour is incorporated. Fold in the peanut butter M&M’s. Lastly, stir in the peanut butter.
    1¼ cups brown sugar, ½ cup granulated sugar, ½ cup unsalted butter, ⅓ cup vegetable oil, 1 large egg, 2 egg yolks, 1 teaspoon pure vanilla extract, 1 cup peanut butter M&M’s, ½ cup creamy peanut butter
  • Smooth the batter into the prepared baking pan. Top with extra peanut butter M&M’s. Place into the oven to bake for 16-18 minutes, or until the edges are golden brown. The center will feel almost unfinished. Do not worry about that as the residual heat will finish baking it. The center of the bars will fall after several minutes on the cooling rack - this is normal.
    how to make m&m peanut butter blondies
  • Once the bars have cooled, slice into 16 squares and serve.
    how to make m&m peanut butter blondies


  • Add extra M&M's on top of the batter before baking the bars. This will give you a little extra sweetness and crunch.
  • Make sure you pat the blondie batter into your prepared dish. This will make sure they cook evenly and will be easier to cut after they cool.
  • Feel free to use your favorite peanut butter for this recipe. If you want to reduce the sugar, you can use sugar-free peanut butter.
Storage: Store M&M peanut butter bars in an airtight container at room temperature for up to 3 days, in the refrigerator for up to 1 week, or in the freezer for up to 3 months


Serving: 1bar | Calories: 336kcal | Carbohydrates: 50g | Protein: 6g | Fat: 13g | Saturated Fat: 7g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 1g | Cholesterol: 37mg | Sodium: 259mg | Potassium: 115mg | Fiber: 1g | Sugar: 32g | Vitamin A: 89IU | Vitamin C: 1mg | Calcium: 49mg | Iron: 2mg